SELECT 
  feature_id, 
  variant_id, 
  value, 
  value_int 
FROM 
  cscart_product_features_values 
WHERE 
  product_id = 1311 
  AND lang_code = 'de'

Query time 0.00059

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_features_values ref lang_code,product_id,product_id_idx,product_feature_idx product_id 3 const 115 Using where

Result

feature_id variant_id value value_int
24 107
59 5877 4.000
42 6256
135 5965
30 6124
136 5975
136 5973
127 5895
128 5899
129 5903
134 5960
135 5968
152 6093
152 6092
152 6091
152 6090
152 6089
136 5972
152 6094
152 6088
152 6095
152 6096
152 6100
152 6101
152 6105
152 6106
178 6311
136 5974
176 6261
136 5976
136 5977